A Tale of Two Combines

by Robert A. Stevens, February 24, 2014

Adpated from “Modeling and Analysis of Row Crop Harvesting Patterns by Combines” by A.C. Hansen, Q. Zhang, and T.A. Wilcox, Transactions of the ASABE, Vol. 50(1):5-12 (2007)

Background Info: Domain Knowledge

Table 1. Summary of equipment, field details, and electronic flags.

Figure 1. Harvesting patterns for single combine in a row crop.

Data

Combine 1

  1. Corn-harvesting.xls (2 tabs)

  2. Corn-harvesting-CAN.csv (CAN tab)

  3. Combine1.pptx

Combine 2

  1. Corn-Harvest-2.xls

  2. Corn-Harvest-2-CAN.csv

  3. Combine2a.pptx (as delivered - records out of time order)

  4. Combine2b.pptx (fixed - records in time order)

Variables Captured

  1. LONGITUDE

  2. LATITUDE

  3. TIME

  4. STATUS (head position: 1 = down, 0 = up)

  5. DRY_YIELD (bushels/acre)

  6. DAYOFMONTH

  7. HOUR

  8. MINUTE

  9. SECOND

  10. SPEED (ground speed in mph)

  11. TORQUE (% of torque at rated)

  12. ENG_SPD (rpm)

  13. CURVE (unloading auger: 1 = off, 2 = engaged)

  14. FUEL (% of maximum?)

  15. FUEL_KG.HR (fuel rate in kg/hour)

  16. GRD_SPD (ground speed in km/hour)

  17. MPH (ground speed in mph)

Load the necessary R packages.

library(ggplot2)  # Used for several of the plots
library(maps)  # Required for correct Lon/Lat projections for ggplot2 coord_map()
library(plyr)  # Used for sorting dataframe to make sure in the correct order
library(ggmap)  # Used for Google Earth style plots
library(rpart)  # Recursive Partitioning data mining routine
library(rpart.plot)  # Improves the rpart plots

Code to add footnotes to all of the plots from “R: Good practice - adding footnotes to graphics”

http://ryouready.wordpress.com/2009/02/17/r-good-practice-adding-footnotes-to-graphics/

# basic information at the beginning of each script
sourceText <- "Source: 'Modeling and Analysis of Row Crop Harvesting Patterns by Combines' by Hansen et al."
scriptName <- "Script: CombineV2.Rmd"
author <- "RAStevens"
footnote <- paste(sourceText, scriptName, format(Sys.time(), "%d %b %Y"), author, 
    sep = " / ")

# default footnote is today's date, cex = 0.7 (size) and color is a kind of
# grey

makeFootnote <- function(footnoteText = format(Sys.time(), "%d %b %Y"), size = 0.7, 
    color = grey(0.5)) {
    require(grid)
    pushViewport(viewport())
    grid.text(label = footnoteText, x = unit(1, "npc") - unit(2, "mm"), y = unit(2, 
        "mm"), just = c("right", "bottom"), gp = gpar(cex = size, col = color))
    popViewport()
}

Load, prepare, and merge the two data sets.

setwd("C:\\Users\\rs62172\\Documents\\Corn\\")  # user specific - need to edit to run
filename <- "Corn-harvesting-CAN.csv"
Combine1 <- read.csv(filename, header = TRUE, as.is = TRUE)
filename <- "Corn-Harvest-2-CAN.csv"
Combine2 <- read.csv(filename, header = TRUE, as.is = TRUE)
Combine2 <- arrange(Combine2, DAYOFMONTH, HOUR, MINUTE, SECOND)  # put in the right time order
Combine1 <- Combine1[, -c(3:4)]  # remove Easting and Northing
dim(Combine1)

## [1] 12013    17

Combine2 <- Combine2[, -c(11)]  # remove TIMELAPSE
dim(Combine2)

## [1] 11519    17

Combine1$Combine <- 1
Combine2$Combine <- 2
Combine12 <- rbind(Combine1, Combine2)
Combine12$Combine <- as.factor(Combine12$Combine)
dim(Combine12)

## [1] 23532    18

mapLon <- median(Combine12$LONGITUDE)
mapLat <- median(Combine12$LATITUDE)

The location is:

revgeocode(c(mapLon, mapLat))

## Information from URL : http://maps.googleapis.com/maps/api/geocode/json?latlng=40.28414,-89.15606&sensor=false
## Google Maps API Terms of Service : http://developers.google.com/maps/terms

## [1] "2313-2399 Old Principal Road, McLean, IL 61754, USA"

Use ggmap with zoom values 10 to 17 to get an idea of where this is:

plotTitle <- "Combine 1 and Combine 2 Paths using ggmap with zoom = 10"
map <- get_googlemap(center = c(lon = mapLon, lat = mapLat), zoom = 10, maptype = "hybrid")

## Map from URL : http://maps.googleapis.com/maps/api/staticmap?center=40.28414,-89.15606&zoom=10&size=%20640x640&maptype=hybrid&sensor=false
## Google Maps API Terms of Service : http://developers.google.com/maps/terms

ggmap(map) + geom_path(data = Combine12, aes(x = LONGITUDE, y = LATITUDE, color = Combine), 
    size = I(1)) + labs(title = paste(plotTitle), x = "Longitude", y = "Latitude")
makeFootnote(footnote)

## Loading required package: grid

plot of chunk ggplot 


plotTitle <- "Combine 1 and Combine 2 Paths using ggmap with zoom = 11"
map <- get_googlemap(center = c(lon = mapLon, lat = mapLat), zoom = 11, maptype = "hybrid")

## Map from URL : http://maps.googleapis.com/maps/api/staticmap?center=40.28414,-89.15606&zoom=11&size=%20640x640&maptype=hybrid&sensor=false
## Google Maps API Terms of Service : http://developers.google.com/maps/terms

ggmap(map) + geom_path(data = Combine12, aes(x = LONGITUDE, y = LATITUDE, color = Combine), 
    size = I(1)) + labs(title = paste(plotTitle), x = "Longitude", y = "Latitude")
makeFootnote(footnote)

plot of chunk ggplot 


plotTitle <- "Combine 1 and Combine 2 Paths using ggmap with zoom = 12"
map <- get_googlemap(center = c(lon = mapLon, lat = mapLat), zoom = 12, maptype = "hybrid")

## Map from URL : http://maps.googleapis.com/maps/api/staticmap?center=40.28414,-89.15606&zoom=12&size=%20640x640&maptype=hybrid&sensor=false
## Google Maps API Terms of Service : http://developers.google.com/maps/terms

ggmap(map) + geom_path(data = Combine12, aes(x = LONGITUDE, y = LATITUDE, color = Combine), 
    size = I(1)) + labs(title = paste(plotTitle), x = "Longitude", y = "Latitude")
makeFootnote(footnote)

plot of chunk ggplot 


plotTitle <- "Combine 1 and Combine 2 Paths using ggmap with zoom = 13"
map <- get_googlemap(center = c(lon = mapLon, lat = mapLat), zoom = 13, maptype = "hybrid")

## Map from URL : http://maps.googleapis.com/maps/api/staticmap?center=40.28414,-89.15606&zoom=13&size=%20640x640&maptype=hybrid&sensor=false
## Google Maps API Terms of Service : http://developers.google.com/maps/terms

ggmap(map) + geom_path(data = Combine12, aes(x = LONGITUDE, y = LATITUDE, color = Combine), 
    size = I(1)) + labs(title = paste(plotTitle), x = "Longitude", y = "Latitude")
makeFootnote(footnote)

plot of chunk ggplot 


plotTitle <- "Combine 1 and Combine 2 Paths using ggmap with zoom = 14"
map <- get_googlemap(center = c(lon = mapLon, lat = mapLat), zoom = 14, maptype = "hybrid")

## Map from URL : http://maps.googleapis.com/maps/api/staticmap?center=40.28414,-89.15606&zoom=14&size=%20640x640&maptype=hybrid&sensor=false
## Google Maps API Terms of Service : http://developers.google.com/maps/terms

ggmap(map) + geom_path(data = Combine12, aes(x = LONGITUDE, y = LATITUDE, color = Combine), 
    size = I(1)) + labs(title = paste(plotTitle), x = "Longitude", y = "Latitude")
makeFootnote(footnote)

plot of chunk ggplot 


plotTitle <- "Combine 1 and Combine 2 Paths using ggmap with zoom = 15"
map <- get_googlemap(center = c(lon = mapLon, lat = mapLat), zoom = 15, maptype = "hybrid")

## Map from URL : http://maps.googleapis.com/maps/api/staticmap?center=40.28414,-89.15606&zoom=15&size=%20640x640&maptype=hybrid&sensor=false
## Google Maps API Terms of Service : http://developers.google.com/maps/terms

ggmap(map) + geom_path(data = Combine12, aes(x = LONGITUDE, y = LATITUDE, color = Combine), 
    size = I(1)) + labs(title = paste(plotTitle), x = "Longitude", y = "Latitude")
makeFootnote(footnote)

plot of chunk ggplot 


plotTitle <- "Combine 1 and Combine 2 Paths using ggmap with zoom = 16"
map <- get_googlemap(center = c(lon = mapLon, lat = mapLat), zoom = 16, maptype = "hybrid")

## Map from URL : http://maps.googleapis.com/maps/api/staticmap?center=40.28414,-89.15606&zoom=16&size=%20640x640&maptype=hybrid&sensor=false
## Google Maps API Terms of Service : http://developers.google.com/maps/terms

ggmap(map) + geom_path(data = Combine12, aes(x = LONGITUDE, y = LATITUDE, color = Combine), 
    size = I(1)) + labs(title = paste(plotTitle), x = "Longitude", y = "Latitude")
makeFootnote(footnote)

plot of chunk ggplot 


plotTitle <- "Combine 1 and Combine 2 Paths using ggmap with zoom = 17"
map <- get_googlemap(center = c(lon = mapLon, lat = mapLat), zoom = 17, maptype = "hybrid")

## Map from URL : http://maps.googleapis.com/maps/api/staticmap?center=40.28414,-89.15606&zoom=17&size=%20640x640&maptype=hybrid&sensor=false
## Google Maps API Terms of Service : http://developers.google.com/maps/terms

ggmap(map) + geom_path(data = Combine12, aes(x = LONGITUDE, y = LATITUDE, color = Combine), 
    size = I(1)) + labs(title = paste(plotTitle), x = "Longitude", y = "Latitude")
makeFootnote(footnote)

plot of chunk ggplot

Explore the data using combine paths and color coding for other variables:

Combine12$Combine <- as.factor(Combine12$Combine)
plotTitle <- "Combine 1 and Combine 2 Paths"
qplot(LONGITUDE, LATITUDE, data = Combine12, geom = "point", color = Combine, 
    size = I(2)) + scale_x_continuous("Longitude") + scale_y_continuous("Latitude") + 
    coord_map() + labs(title = paste(plotTitle), x = "Longitude", y = "Latitude")
makeFootnote(footnote)

plot of chunk unnamed-chunk-5 


plotTitle <- "Harvest Pattern for Combines 1 and 2 with CURVE (unloading auger:  1 = off, 2 = engaged)"
Combine12$CURVE <- as.factor(Combine12$CURVE)
qplot(LONGITUDE, LATITUDE, data = Combine12, geom = "point", color = CURVE, 
    size = I(2)) + scale_x_continuous("Longitude") + scale_y_continuous("Latitude") + 
    coord_map() + labs(title = paste(plotTitle)) + facet_grid(. ~ Combine)
makeFootnote(footnote)

plot of chunk unnamed-chunk-5 


plotTitle <- "Harvest Pattern for Combines 1 and 2 with STATUS (head position:  1 = down, 0 = up)"
Combine12$STATUS <- as.factor(Combine12$STATUS)
qplot(LONGITUDE, LATITUDE, data = Combine12, geom = "point", color = STATUS, 
    size = I(2)) + scale_x_continuous("Longitude") + scale_y_continuous("Latitude") + 
    coord_map() + labs(title = paste(plotTitle)) + facet_grid(. ~ Combine)
makeFootnote(footnote)

plot of chunk unnamed-chunk-5 


plotTitle <- "Harvest Pattern for Combines 1 and 2 with Dry Yield (bushels/acre)"
qplot(LONGITUDE, LATITUDE, data = Combine12, geom = "point", color = DRY_YIELD, 
    size = I(2)) + scale_x_continuous("Longitude") + scale_y_continuous("Latitude") + 
    coord_map() + labs(title = paste(plotTitle)) + facet_grid(. ~ Combine) + 
    scale_colour_gradientn(colours = rainbow(7))
makeFootnote(footnote)

plot of chunk unnamed-chunk-5 


plotTitle <- "Dry Yield Histograms (Combine 1 = Red, Combine 2 = Blue)"
ggplot(Combine12, aes(x = DRY_YIELD)) + geom_histogram(data = subset(Combine12, 
    Combine == 1), fill = "red", alpha = 0.2) + geom_histogram(data = subset(Combine12, 
    Combine == 2), fill = "blue", alpha = 0.2) + labs(title = paste(plotTitle), 
    x = "Dry Yield (bushels/acre)") + theme_bw()

## stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
## stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.

makeFootnote(footnote)

plot of chunk unnamed-chunk-5 


plotTitle <- "Harvest Pattern for Combines 1 and 2 with Engine Speed (rpm)"
qplot(LONGITUDE, LATITUDE, data = Combine12, geom = "point", color = ENG_SPD, 
    size = I(2)) + scale_x_continuous("Longitude") + scale_y_continuous("Latitude") + 
    coord_map() + labs(title = paste(plotTitle)) + facet_grid(. ~ Combine) + 
    scale_colour_gradientn(colours = rainbow(7))
makeFootnote(footnote)

plot of chunk unnamed-chunk-5 


plotTitle <- "Engine Speed Histograms (Combine 1 = Red, Combine 2 = Blue)"
ggplot(Combine12, aes(x = ENG_SPD)) + geom_histogram(data = subset(Combine12, 
    Combine == 1), fill = "red", alpha = 0.2) + geom_histogram(data = subset(Combine12, 
    Combine == 2), fill = "blue", alpha = 0.2) + labs(title = paste(plotTitle), 
    x = "Engine Speed (rpm)") + theme_bw() + xlim(2100, 2500)

## stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
## stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.

## Warning: position_stack requires constant width: output may be incorrect
## Warning: position_stack requires constant width: output may be incorrect

makeFootnote(footnote)

plot of chunk unnamed-chunk-5 


plotTitle <- "Harvest Pattern for Combines 1 and 2 with TORQUE (% of torque at rated)"
qplot(LONGITUDE, LATITUDE, data = Combine12, geom = "point", color = TORQUE, 
    size = I(2)) + scale_x_continuous("Longitude") + scale_y_continuous("Latitude") + 
    coord_map() + labs(title = paste(plotTitle)) + facet_grid(. ~ Combine) + 
    scale_colour_gradientn(colours = rainbow(7))
makeFootnote(footnote)

plot of chunk unnamed-chunk-5 


plotTitle <- "TORQUE Histograms (Combine 1 = Red, Combine 2 = Blue)"
ggplot(Combine12, aes(x = TORQUE)) + geom_histogram(data = subset(Combine12, 
    Combine == 1), fill = "red", alpha = 0.2) + geom_histogram(data = subset(Combine12, 
    Combine == 2), fill = "blue", alpha = 0.2) + labs(title = paste(plotTitle), 
    x = "TORQUE (% of torque at rated)") + theme_bw()

## stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
## stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.

makeFootnote(footnote)

plot of chunk unnamed-chunk-5 


plotTitle <- "Harvest Pattern for Combines 1 and 2 with Ground Speed (mph)"
qplot(LONGITUDE, LATITUDE, data = Combine12, geom = "point", color = MPH, size = I(2)) + 
    scale_x_continuous("Longitude") + scale_y_continuous("Latitude") + coord_map() + 
    labs(title = paste(plotTitle)) + facet_grid(. ~ Combine) + scale_colour_gradientn(colours = rainbow(7))
makeFootnote(footnote)

plot of chunk unnamed-chunk-5 


plotTitle <- "Ground Speed Histograms (Combine 1 = Red, Combine 2 = Blue)"
ggplot(Combine12, aes(x = MPH)) + geom_histogram(data = subset(Combine12, Combine == 
    1), fill = "red", alpha = 0.2) + geom_histogram(data = subset(Combine12, 
    Combine == 2), fill = "blue", alpha = 0.2) + labs(title = paste(plotTitle), 
    x = "Ground Speed (mph)") + theme_bw()

## stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
## stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.

makeFootnote(footnote)

plot of chunk unnamed-chunk-5 


plotTitle <- "Harvest Pattern for Combines 1 and 2 with Fuel Rate (kg/hour)"
qplot(LONGITUDE, LATITUDE, data = Combine12, geom = "point", color = FUEL_KG.HR, 
    size = I(2)) + scale_x_continuous("Longitude") + scale_y_continuous("Latitude") + 
    coord_map() + labs(title = paste(plotTitle)) + facet_grid(. ~ Combine) + 
    scale_colour_gradientn(colours = rainbow(7))
makeFootnote(footnote)

plot of chunk unnamed-chunk-5 


plotTitle <- "Fuel Rate Histograms (Combine 1 = Red, Combine 2 = Blue)"
ggplot(Combine12, aes(x = FUEL_KG.HR)) + geom_histogram(data = subset(Combine12, 
    Combine == 1), fill = "red", alpha = 0.2) + geom_histogram(data = subset(Combine12, 
    Combine == 2), fill = "blue", alpha = 0.2) + labs(title = paste(plotTitle), 
    x = "Fuel Rate (kg/hour)") + theme_bw()

## stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
## stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.

makeFootnote(footnote)

plot of chunk unnamed-chunk-5

Now try some data mining with Recursive Partitioning (rpart):

FuelRate.rp <- rpart(FUEL_KG.HR ~ STATUS + DRY_YIELD + TORQUE + ENG_SPD + CURVE + 
    MPH + Combine, data = Combine12, cp = 0.001)
plotcp(FuelRate.rp)
makeFootnote(footnote)

plot of chunk unnamed-chunk-6

The last node just crosses the threhold, so no need to prune the tree.

FuelRate.rp

## n= 23532 
## 
## node), split, n, deviance, yval
##       * denotes terminal node
## 
##   1) root 23532 593500.00 29.320  
##     2) TORQUE< 65.5 11059 163200.00 25.490  
##       4) TORQUE< 55.5 2914  36140.00 21.000  
##         8) TORQUE< 46.5 1028  11760.00 18.080  
##          16) ENG_SPD< 1985 20    101.50  2.731 *
##          17) ENG_SPD>=1985 1008   6857.00 18.380  
##            34) ENG_SPD< 2372 879   3652.00 17.850  
##              68) TORQUE< 40.5 339   1096.00 16.320 *
##              69) TORQUE>=40.5 540   1265.00 18.810 *
##            35) ENG_SPD>=2372 129   1267.00 22.000 *
##         9) TORQUE>=46.5 1886  10780.00 22.600  
##          18) ENG_SPD< 2316 210   1251.00 19.060 *
##          19) ENG_SPD>=2316 1676   6567.00 23.040  
##            38) TORQUE< 51.5 688   2570.00 21.970  
##              76) ENG_SPD< 2354 489    673.60 21.210 *
##              77) ENG_SPD>=2354 199    902.40 23.860 *
##            39) TORQUE>=51.5 988   2662.00 23.790  
##              78) CURVE=1 927   1672.00 23.540 *
##              79) CURVE=2 61     63.55 27.560 *
##       5) TORQUE>=55.5 8145  47430.00 27.090  
##        10) CURVE=1 7014  20650.00 26.400  
##          20) TORQUE< 60.5 2825   6470.00 25.210  
##            40) ENG_SPD< 2288 30    202.70 18.890 *
##            41) ENG_SPD>=2288 2795   5054.00 25.280  
##              82) ENG_SPD< 2364 2733   3537.00 25.190  
##               164) TORQUE< 57.5 935    955.00 24.410 *
##               165) TORQUE>=57.5 1798   1717.00 25.600 *
##              83) ENG_SPD>=2364 62    640.50 29.000 *
##          21) TORQUE>=60.5 4189   7474.00 27.200  
##            42) ENG_SPD< 2272 28    277.70 19.850 *
##            43) ENG_SPD>=2272 4161   5674.00 27.250  
##              86) TORQUE< 63.5 2478   2737.00 26.850  
##               172) ENG_SPD< 2324 1291    901.10 26.350 *
##               173) ENG_SPD>=2324 1187   1150.00 27.400 *
##              87) TORQUE>=63.5 1683   1951.00 27.840 *
##        11) CURVE=2 1131   2450.00 31.400  
##          22) TORQUE< 61.5 405    549.20 30.100 *
##          23) TORQUE>=61.5 726    832.20 32.130 *
##     3) TORQUE>=65.5 12473 123600.00 32.720  
##       6) CURVE=1 10326  71650.00 31.930  
##        12) TORQUE< 73.5 4500  13980.00 29.870  
##          24) TORQUE< 69.5 2511   5360.00 29.050  
##            48) ENG_SPD< 2306 916   1804.00 28.180  
##              96) ENG_SPD< 2253 12    112.60 20.320 *
##              97) ENG_SPD>=2253 904    941.10 28.280 *
##            49) ENG_SPD>=2306 1595   2448.00 29.560 *
##          25) TORQUE>=69.5 1989   4807.00 30.910  
##            50) ENG_SPD< 2294 698   1686.00 29.880 *
##            51) ENG_SPD>=2294 1291   1980.00 31.470 *
##        13) TORQUE>=73.5 5826  23880.00 33.520  
##          26) TORQUE< 79.5 3890  10170.00 32.880  
##            52) ENG_SPD< 2288 1859   4130.00 32.060  
##             104) ENG_SPD< 2230 14    123.80 23.970 *
##             105) ENG_SPD>=2230 1845   3083.00 32.120  
##               210) TORQUE< 76.5 767   1122.00 31.380 *
##               211) TORQUE>=76.5 1078   1243.00 32.650 *
##            53) ENG_SPD>=2288 2031   3657.00 33.620  
##             106) TORQUE< 76.5 1239   1717.00 33.100 *
##             107) TORQUE>=76.5 792   1061.00 34.450 *
##          27) TORQUE>=79.5 1936   8829.00 34.820  
##            54) ENG_SPD< 2282 1312   5552.00 34.230  
##             108) TORQUE< 83.5 865   1963.00 33.650 *
##             109) TORQUE>=83.5 447   2729.00 35.360 *
##            55) ENG_SPD>=2282 624   1878.00 36.050 *
##       7) CURVE=2 2147  14440.00 36.530  
##        14) TORQUE< 72.5 1028   2522.00 34.520  
##          28) TORQUE< 69.5 671    963.40 33.840 *
##          29) TORQUE>=69.5 357    665.90 35.800 *
##        15) TORQUE>=72.5 1119   3975.00 38.370  
##          30) TORQUE< 75.5 392    803.50 37.190 *
##          31) TORQUE>=75.5 727   2336.00 39.000 *

Note: the only variables that appear are TORQUE, ENG_SPD and CURVE (unloading auger: 1 = off, 2 = engaged).

plotTitle <- "rpart Results for Fuel Rate (kg/hour)"
plot(FuelRate.rp, main = plotTitle)
text(FuelRate.rp, digits = 4, cex = 0.65)
makeFootnote(footnote)

plot of chunk unnamed-chunk-8

That's hard to read, so try “prp” (pretty rpart):

plotTitle <- "rpart Results for Fuel Rate (kg/hour) using prp"
prp(FuelRate.rp, main = plotTitle)
makeFootnote(footnote)

plot of chunk unnamed-chunk-9

That's better, but still difficult to explain, so try enhancing prp:

plotTitle <- "rpart Results for Fuel Rate (kg/hour) using prp Enhanced"
prp(FuelRate.rp, type = 2, nn = TRUE, fallen.leaves = TRUE, faclen = 0, varlen = 0, 
    shadow.col = "grey", branch.lty = 3, main = plotTitle)
makeFootnote(footnote)

plot of chunk unnamed-chunk-10

Now plot all 4 variables on one plot: ENG_SPD, TORQUE, CURVE and Fuel Rate. Played around with ggplot2's “alpha” and “size” to create a pseudo contour plot.

plotTitle <- "ENG_SPD versus TORQUE by CURVE (unloading auger:  1 = off, 2 = engaged)"
qplot(ENG_SPD, TORQUE, data = Combine12, color = FUEL_KG.HR, alpha = I(1/4), 
    size = I(4)) + facet_grid(. ~ CURVE) + labs(title = paste(plotTitle)) + 
    scale_colour_gradientn(colours = rainbow(7)) + theme_bw()
makeFootnote(footnote)

plot of chunk unnamed-chunk-11

Even though Combine didn't show up in the data mining results, put in in anyway to see what it looks like.

plotTitle <- "ENG_SPD versus TORQUE by CURVE (columns) and Combine (rows)"
qplot(ENG_SPD, TORQUE, data = Combine12, color = FUEL_KG.HR, alpha = I(1/4), 
    size = I(4)) + facet_grid(Combine ~ CURVE) + labs(title = paste(plotTitle)) + 
    scale_colour_gradientn(colours = rainbow(7)) + theme_bw()
makeFootnote(footnote)

plot of chunk unnamed-chunk-12

It seems the two combines performed differently because they had different levels of Engine Speed and Torque - but why?

Still work to do

All along the way, review results with engineers: